M400 Series electromagnetic locks from Schlage are designed with the customer in mind to be robust, easy-to-install, and secure. The unique bayonet mounting feature makes installation easier, allowing the installer to have their hands free during the mounting process. All M400 Series electromagnetic locks are symmetrical with field-selectable handing, allowing optimum placement of the magnet, no matter the application. They are designed to provide automatic voltage sensing for 12 and 24 V along with polarity protection to make wiring less complex. M490 models are tested and certified to meet or exceed UL 1034 and BHMA 1500 lb hold force requirements. "Plus" models offer magnetic bond sensor (MBS), adjustable relock time delay (RTD) and door position switch (DPS). Automatic voltage selection (AVS) is standard. Armature mount pivot feature compensates for slight opening imperfections.